Muffler



Jan 9, 1940- R. o. BERG Er AL 2,186,062

MUFFLER Filed July 25, 1938 2 Sheets-Sheet l INVENTORS 9 Simon Se rg Frdtjof FI Berg ,p wss ATTORNEYS Richard O. Ber

Jan. 9, 1940.

R. O. BERG ET AL MUFFLER Filed July 25, 1938 Y 2 Sheets-Sheet 2 INVENTORS icfarc O. Berg Simon Be r9 dijo( Ber Huy-Mw# ATTORNEYS Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE MUFFLER Michigan Application July 25, 1938, Serial No. 221,146

11 Claims.

This invention has to do with a muffler especially useful for mufling sounds of the exhaust gases of internal combustion engines. The invention is concerned particularly with the provi- Sion of a muflier useful on automotive vehicles, although the invention may be used with internal combustion engines wherever such engines are employed.

The patented art onv muiiiers for this purpose contains many disclosures and advances quite a number of theories as to the function and operation of some of the mui'liers. However, 'there are only a few essentials in the production of a good and commercially acceptable muflier; one is that its muflling qualities should be goed from the standpoint of reducing or minimizing the noise of the exhaust; another is that the back pressure created on the engine must be low so as to not interfere with engine operation; and the construction should preferably be such that the muffler can be manufactured at such a cost that it is capable of being put to use to thereby benefit the public.

It is the principal object of this invention to provide a mufder which meets these requirements. A muffler constructed in accordance with this invention, such as the one shown herein for exemplifying the invention, has been found, by comparative tests, with muffler constructions now in use, to have a better muilling action, and at the same time, the muier of this invention creates a lower back pressure on the engine, resulting in better engine operation.

The construction of this muliler is not greatly complicated, and employs but a few parts which are of different construction (some of the parts are identical so that their production is facilitated), and the construction is one which facilitates assembly.

These and other objects will be more denitely appreciated as the following detailed description is followed in connection with the accompanying drawings which illustrate one muffler made in accordance with the invention.

Fig. l is a general view of the muier with parts cut away illustrating the interior construction.

Fig. 2 is a cross sectional View taken substantially o-n line 2 2 of Fig. l.

Figs. 3 to 8, inclusive, are cross sectional views taken on lines 3 3 to 8 8 inclusive on Fig. 1, illustrating progressive variation in construction substantially from one end to thev other oi the muffler.

Fig. 9 is an enlarged cross sectional view taken substantially on line 9 9 of Fig. l. illustrating a joint construction.

Fig. 10 is an enlarged cross sectional view taken substantially on line I l0 of Fig. 1.

Fig. 11 is an enlarged cross sectional view taken substantially on line H il 0f Fig. 1.

Fig. 12 is an enlarged cross sectional view taken substantially on line l2 |2 of Fig. 1.

Fig, 13 is an enlarged cross sectional view taken substantially on line 13 I3 of Fig. 2.

Fig. 14 is a cross sectional view similar to Fig. 13 taken substantially on line |4 I4 of Fig. 3.

Fig. 15 is an enlarged cross sectional View showing a joint structure taken substantially on line ls-ls of Fig. 1. 15

The muiiler shown comprises an outer shell I which may be cylindrical in form and which preferably has a laminated wall of two layers of metal as shown in Fig. 15. There is an end head 2 at one end and an end head 3 at the other, and these end heads may be secured to the end portions of the outer wall by a seam such as illustrated at 8 in Fig. 15. These seams may be the same at each end.

An inlet pipe for the exhaust gases is illustrated at 4 and extends through the end head 2, and the tube and end head may be welded together as at 5. An outlet or exhaust tube B extends through the end head 3 and may be welded thereto as at 1. 30

The interior of the shell is divided by a plurality of transverse plates each having holes or passageways therein; one plate positioned adjacent the inlet end of the shell is illustrated at I El, and the other plates which are disposed in spaced relation are shown at l to I6 inclusive. The plates are similar in construction and each has a lia-nge 2!! litting inside the shell and may be spot welded to the shell. As shown in Figs. 2 to 8, inclusive, each plate is provided with a series of apertures 2l arranged or concentrated, so to speak, in a side portion thereof, as shown. These apertures are preferably formed by extruding the metal to leave a projecting collar or fillet 22. The plates Ii! yand i6 may be identical, but are disposed in reverse position. Plates Il, l2 and I3 may be identical, and plates M and l5 may be identical. The projecting portions 22 on plate Il) extend forwardly toward a resonance chamber 25 disposed between the end head 2 and plate I0. The fillets or collars on all the other plates extend rearwardly, and at the rear end of the muffler is a resonance chamber 2S disposed between end head 3 and plate I6.

For convenience in considering the invention further, the several chambers or compartments between the plates are identiiied by the reference characters a, b, c, d, c, and j'. Some plates have eccentrically disposed apertures, arranged in two aligned groups. One group is for the reception of inlet tube which may be a separate tube formh ing an extension of the inlet tube il. The apertures for these tubes may be flanged as illustrated at 4l. As shown in Fig. 9 the end of the 'tube lll may be telescoped in the extension l, and the combined thickness of these metal parts may substantially equal the thickness of the tube il, and

a weld connection may be made at the abutting l in Fig. 9, except reversed as toposition.

e, and three in chamber f.

The inlet tube 4D has a group of passageways formed therein, each group being located in one of the chambers a to f inclusive. The number of apertures in the group progressively varies from end to end. The outlet tube i5 has groups of apertures with a group located in each of the chambers c to f, inclusive, with the numbers of the apertures progressively varying in each cham-- ber but in the reverse manner. For example, in one muflerl construction which has been found satisfactory for a certain engine, the tube til is provided with twenty-seven passageways in the chamber a, twenty-one in the chamber b, fteen in chamber c, nine in chamber d, six in chamber The outlet tube #l5 is just the reverse, the number of apertures in each group being three in chamber a, six in chamber b, nine in chamber c, fifteen in chamber d, twenty-one in chamber e, and twenty-seven in cham ber f. Of course, it will be appreciated that the muiiler may be made in different sizes and capacities, and the number of chambers, the overall diameter, and length of the muffler shell and the number of the apertures in the inlet and outlet tube may Vary. The combined capacity of the apertures in the inlet and outlet tubes preferably equals or exceeds the capacity of the inlet and outlet tubes 4 and 6.

By reference to Figs. 2 to 8. inclusive, it will be noted that the inletr and outlet tubes are disposed eccentrically of the muler shell. The apertures in theinlet tube are generally illustrated by the character 5i! while those in the outlet tube are generally illustrated by the reference character 5I. The exhaust gases entering the inlet tube pass out through the apertures ll.

In making the assembly the plates I4, l5 and H5 may be assembled from one end of the shell; it will be observed that the flanges 2l) form trailing edges to facilitate this assembly. The plates I, Il, l2 and 53 may be assembled from the other end of the shell and the direction of the flanges 2G is reversed. When the plates are located the flanges may be Welded to the shell. The inlet and outlet tubes are pushed into posiu tion from opposite ends of the shell and at this time the end plates Il] and I6 are respectively connected to the inlet and outlet tube structures and are assembled at thev same time. Subsequently the heads may be located and the weld connections made at 5 and l.

In the operation of the mulfler Yexhaust gases, of course, enter through the tube 4, but the end of the tube All is closed. Therefore, the gases pass through the apertures 5B, through the apertures 5| into the outlet tube 45 and then out through the exhaust pipe t. The capacity of each group of apertures in the inlet tube in chambers a, b and c exceeds the capacity of each group of apertures in the outlet tube, with a progressive change approaching balanced relation. The capacity of each group of apertures in the inlet tube in chambers d, e and f is less than the capacity of each group of apertures in the outlet tube, with the differential being in a progressive relation. And, in the end, the capacity of all the apertures in the inlet and outlet tubes is preferably balanced Therefore, some of the gases entering the chamber a will pass into the outlet tube but some will be obliged to travel through the apertures in the plate ll into chamber Z). Some of these gases plus gases entering chamber h from the outlet apertures in the tube 4 Will be obliged to pass through the plate l2 into chamber c. Some of the gases in chamber c will be obliged to pass into chamber d. All the while, however, larger volumes of gases enter the outlet tube in each chamber. This action continues through chamber e and nally into chamber f, at which time the total capacity of the tubes is balanced. This causes a mixing or diffusion of the gases, as some of the gases flow generally across the chambers and some move lengthwise through the shell. There is no direct flow of gases into the resonance chamber 25 although the apertures in the plate lll form a connection therewith, and

the trapped gases or air in chamber 25 serves as a cushion. The same thing is true of the resonance chamber 26. The collars or projections 22 on all the plates, except plate IQ, extend rearwardly so thatow of gases throughy the apertures 2l is facilitated. Even the gases which pass lengthwise through the several plates are given some transverse movement because of the eccentric location of the inlet and outlet tubes and the concentration of the apertures 2! upon one side of the plates.

substantially uniformly from end to end. This eliminates points of concentrated heat which would indicate trapping hot gases at the highly heated point.

the muffler is not functioning uniformly, and such objectionable feature may be productive of poor muling action or high back pressure, and in time Where a muler isheated excessively at one or more points, the indication is that This is ascertained by the fact that in use the muler is heated i the concentration of heat at a localized point or combustion engine comprising, a shell, an inlet tube for exhaust gases extending into the shell, an outlet tube for exhaust gases extending out of the shell, said inlettube and outlet tube being disposed in overlapping relation within the shell,y

the inlet tube having apertures therein progressively diminishing in number in one direction, the outlet tube having apertures therein progressively diminishing in number in the opposite direction, whereby the gases pass from the inlet tube to the outlet tube through said apertures and whereby some o the gases are caused to ow within vthe shell in the direction of extent oi the inlet and outlet tubes.

2. A muffler for exhaust gases of an internal combustion engine comprising, a shell, an inlet tube in the shell entering one side thereof, an outlet tube in the shell passing out through the opposite side thereof, said inlet and outlet tubes being disposed in overlapping relationship within the shell, the inlet tube having apertures through itsfwall in that portion which overlaps the outlet tube, the outlet tube having apertures in its wall in that portion which overlaps the inlet tube, said apertures in the inlet tube progressively diminishing in number from near the inlet side towards the end oi the tube and the apertures in the outlet tube progressively increasing in number from its end toward the outlet.

3; A muffler for exhaust gases of an internal combustion engine comprising, a shell, an inlet tube in the shell. entering one side thereof, an outlet tube in the shell passing out through the opposite side thereof, said inlet and outlet tubes being disposed in overlapping relationship within the shell, the ends of the inlet and outlet tubes being closed, the inlet tube having apertures through its wall in that portion which overlaps the outlet tube, the outlet tube having apertures in its wall in that portion which overlaps the inlet tube, said apertures in the inlet tube progressively diminishing in number from near the inlet side towards the end of the tube and the apertures in the outlet tube progressively decreasing in number from near the outlet side toward its end.

4. A muffler for exhaust gases of an internal combustion engine comprising, a shell, an inlet tube in the shell entering one side thereof, an outlet tube .in the shell passing out through the opposite side thereof, said inlet and outlet tubes being disposed in overlapping relationship within the shell, the ends oi the inlet and outlet tubes being closed, the inlet tube having apertures through its wall in that portion which overlaps the outlet tube, the outlet tube having apertures in its wall in that portion which overlaps the inlet tube, said apertures in the inlet tube progressively diminishing in number from near the inlet side towards the end oi the tube and the apertures in the outlet tube progressively increasing in number from its end toward the outlet, the total capacity of the apertures in the inlet tube and outlet tube being substantially the same.

5. A muler for exhaust gases of an internal combustion engine comprising, a cylindrical shell having closure heads at opposite ends, an inlet tube extending through one end of the head and terminating short of the opposite end head and having a closed end, an outlet tube extending through said opposite end head and terminating near the rst mentioned end head and having a closed end, said tubes having apertures in their side walls extending throughout the major portion or the length of the shell, with the number of the aperturesI in the inlet tube progressively diminishing toward its closed end and with the number ci the apertures in the outlet tube progressively increasing from its closed end toward its outlet end, both of said tubes being located substantially on one side of a center line of the shell.

6. A muffler for exhaust gases of an internal combustion engine comprising, a cylindrical shell having closure heads at opposite ends, an inlet tube extending through one end of the head and terminating short of the opposite end head and having a closed end, an outlet tube extending through said'opposite end head and terminating near the rst mentioned end head and having a closed end, said tubes having apertures in their side walls extending throughout the major portion the length of the shell, with the number of the apertures in the inlet tube progressively diminishing toward its closed end and with the number of the apertures in the outlet tube progressively increasing from its closed end toward its outlet end, both ofv said tubes being located substantially on one side of a center line of the shell, and a plurality of transverse plates in the shell dividing the same into chambers, and each plate having a group of apertures therein located on the opposite side of said center line.

'7. A muiller for exhaust gases of an internal combustion engine comprising, a shell, a forward end head, a rearward end head, a plurality of axially spaced plates dividing the shell into chambers, said plates having at least one aperture therein for interconnecting the chambers, an inlet tube extending through the forward end head and extending through the plates and having a closed end, an outlet tube extending through the rear end head extending through the plates and having a closed end, said inlet tube having groups of apertures with a group leading to each of several chambers, said outlet tube having groups of apertures with a group leading to each of several chambers, the numbers of apertures in the said groups in the inlet tube and the outlet tube progressively diminishing toward their closed ends.

8, A muffler for exhaustgases of an internal combustion engine comprising, a shell with a forward end head and a rearward end head, a plurality of spaced plates in the shell dividing the same into chambers, one or more passageways in each oi at least the intermediate plates for interconnecting the chambers, an inlet tube extending through the forward end head and through said plates and having a closed end, an outlet tube extending through the rear end head and through said plates and having a closed end, the inlet tube having gas passageway means through its wall in each kof several chambers, the outlet tube having gas passageway means through its wall in each of several chambers, the capacity oi the gas passageways in the inlet tube substantially progressively diminishing from the chamber adjacent the forward end head to the chamber adjacent the end of the inlet tube, and the capacity of the gas passageway means in the outlet tube progressively increasing in the same direction in said same chambers.

9. A muler for exhaust gases of an internal combustion engine comprising, an outer shell having opposite end heads, a plate adjacent each end. of the shell having apertures therein and defining a resonance chamber at opposite ends or the shell, a plurality of spaced plates between the first two mentioned plates dividing the shell into intermediate chambers, said second named plas having gas passageways therein for interconnecting the intermediate chambers, an inlet tube extending through one end of the shell through the adjacent resonance chamber intermediatechambers and having-a yclosed end terminating adjacent the opposite resonance chamber, an'outlet tube extending through the opposite end of the shell, through the adjacent resonance chamber, and having a closed end terminating adjacent the first mentioned resonance chamber, each tube having gas-passageway means through` its wall in each of the intermediate chambers, the capacity of the gas passageway means in both the inlet and outlet tubes substantially progressively diminishing toward their closed ends.

10. A muilier for exhaust gases of an internal combustion engine comprising, a shell having for-l ward 'and rearward ends, a plurality of spaced plates dividing the shell into chambers, the end plates being spaced from the adjacent end heads to deneend resonance chambers, and the other plates defining intermediate chambers, all of said plates having a group of apertures therein disposed substantially on one side of a center line through the shell, an inlet tube extending through they forward head and having a closed end terminating substantially at the resonance chamber at the rearward end, anv outlet tube ex tending tliroughl the rearward end andhaving a closed end terminating substantially at the resonance chamber at the `forward end, said inlet and outlet tubes being disposed substantially on one side of a center line through the shell opposite that side containing the apertures in the plates, said inlet tube having a group of apertures in each intermediate chamber with the number of apertures in each group progressively diminishingy toward its closed end and the outlet tube having a group of apertures in each intermediate chamber with the number of apertures in each group progressively diminishing toward its closed end.

l1. A muffler for exhaust gases of an internal combustion engine comprising, a shell having forward and rearward ends, a plurality of apertured plates dividing the shell into chambers, an inlet tube extending through the forward end of the shell and extending through a plurality of said chambers, an outlet tube extending through the rear end of the shell and through a plurality of said chambers, each tube having gas passageway means in its wall communicating into a plurality of said chambers, the capacity of the gas passageway means substantially progressively varying lengthwise of the tubes With the capacity diminishing in the inlet tube in a direction toward the rear of the shell, and increasing inthe outlet tube in the same direction.

RICHARD O. BERG. SIMON BERG. FRIDTJOF BERG.v 

